Annealing furnace



May 19,1936.

C. B. HOAK ANNEALING FURNACE Filed June 11, 1935 3 Sheets-Sheet 1 4 \x 9 l? f 6 A N ,L y i 2 HHHHIHHMHQH NHUHH HEI @manier O'. Hoa/"r Bym A Homey May 19, 1936. c. B. HOAK 2,040,994

ANNEALING FURNACE v Filed June 11, 1935 s sheets-sheet 2 f/Cg/p. 2. 20

Inventor A Homey May 19, 1936. V C B HOAK 2,040,994

ANNEALING FURNACE Filed June 11, 1955 3 Sheets-Sheet 3 nvenlor A Homey Patented. May. `19, 1936 vUNITED sTATEs PATENT OFFICE Appl!catiolxrilnll., lljzi-asl) No. 26,049

My invention relates generally to an annealing furnace especially adapted to the heat treating of sheet steel and tin, and particularly to a furnace of this type which applies uniform heat to the top, bottom and sides of the material being treated.

Another importantl object of my invention is to provide an annealing'furnace of the character indicated above in which oxidizing of the material being treated is positively obviated.

Another important object of my invention is to provide an annealing furnace of the character indicated above in which conservation of and effective use of heat and fuel is attained to an unusual degree.

Other important objects of my invention will be apparent from a reading of the following description in connection with the drawings, wherein for purposes of illustration I have shown a preferred embodiment of my invention.

In the drawings:-

Figure 1 is an elevational view vof the complete furnace.

Figure 2 is a transverse vertical sectional view through the furnace showing covers and stands used for holding tin plate while the same is being annealed in the'furnace.

Figure 3 is a horizontal sectional view taken on the line 3-3 of Figure 2, but with the covers removed from the bases 9. 1

Figure 4 is a section taken approximately on the line 4--4 of Figure 2, but with the bases and covers omitted, the section being taken through the cover only.

Figure 5 is a perspective vi`ew of one of thel fuel distributing tile.

Figure 6 is a' perspective view of a plate of material to be treated. Figure 7 is a fragmentary perspective view of a corner of the lower part bfV one of the stand covers. Referring in detail 'to the drawings, the nu,- meral l generally designates the eoverof the furnace which rests on the base 9 and forms the annealing chamber 1, on the steel oor 8 Iof which rest the stands which include the legged bases 9, the covers having the side wallsLIIl, the closed top II and the reinforcing Ts I2,

the walls Il, the top Il and the b ase 9 forming.

anair-tight enclosureNformthe stacked Asheet metal I3.

Each of the stands includes va base 9 the arrangement and formation of which is subsequently described herein. Resting on eachV base is the cover. which is of appropriate steel of heat resisting character` and includes the vertical side walls III, and the closed top which is integral with the upper edges thereof. The side walls are provided with suitably connected vertical Ts I2A which taper outwardly and have their widest 5 ends at the lower end of the cover and on a level with the lower end of the cover so as to engage the top of the base 9 and furnishextra support for the side walls, and thereby assist in preventing warping of the side walls which would other- 10 Wise take place and cause leaks tinto the interior of the cover which would militate against perfect sealing ofthe sheets within the cover.

Attached to the outer edge of the Ts is the vvertical fence I2' which has itslower edge on 15 a level with the lower edge of the Ts and the lower edge of the side walls. 'This fence is provided as a means to hold sand I I in position on the base 9 and in proper sealing relation to the lower end of the cover; It will be understood 20 that the sand is so arranged that upon slight warping of the lower edge of the cover the sand will act as an automatic seal to prevent leaks into the interior of the cover. The same construction of cover is utilized if, instead of the, 25 two covers shown in the drawings, a single large' cover, especially in annealing steel plates, is utillzed.

It will be observed that the achievement of heating the material on all four sides at a uni- 30 form temperature greatly speeds up the process of annealing and produces a material having a more uniform grain, and all of this isaccomplished at a corresponding saving in fuel over present equipment. 35

The cover 5 comprises the outer shell Il of steel, lined with insulating material I5 of suitable character. The fuel directing tile I8 may be of carborundum tile or of suitable alloy steel of high heat resisting quality. The top of the 40 tile is beveled as indicated by the numeral II to fit the `interior of the insulating material I5, and the radially outward side of the tile has'an opening I8 near its top and the radially inward .side thereof has a fuel outlet opening I9 near 45 its lower end and on a level just below the top of the bases 9 of the stands. The tile I9 deflne l the annealing chamberas'-well as the four combustion chambers-at ltlfeffradially outward sides of the'jtilefwhich combustion chambers are de- 50 properly placed on the base 6. The bottoms of the tile rest on brick which in turn rest on the inner flange I of the bottom of the shell Il. This arrangement of the cover relative to the base enables removing the cover wherever necessary and makes it unnecessary to move the base when it is desired to move or remove the cover for any purpose.

The base which is generallyiesignated 6 comprises the outer cruciform steel shell 2| and lined with suitable insulating material 22 so as to dene the combustion chambers 23 which communicate with the bottom of the combustion chambers 24 in the top of the furnace. The centralized steel floor 8 which forms the rest for the stand bases has a central flue opening 26. As disclosed in Figure 2, each chamber 23 has a number of gas burner openings 21 which lead thereinto near the bottom.

Thel stand bases 9 are of suitable heat resisting material and are spaced upwardly from the ,platform 8 by legs 28 which permit the heat to pass under the bases and do not in any way prevent the gases from passing to the ilue 26.

. It may be remarked here that when treating steel instead of tin sheets, and a single large stand and a single large cover lis being utilized, although the base is disposed directly over the top opening of the iiue 26, the legged Vbase nevertheless pro, vides for free access of the gases to the ilue.

It is obvious that the covers H which prevent the ingress of gases to the material being treated prevent the oxidation of such material which would render the same usless for certain pmposes.

It is obvious that the burning fuel in the combustion boxes 24 enters the top opening I8 in the tile and moving downwardly passes into the heating chamber by way of the openings I9 in the lower end of the tile and then after circulating inthe heating compartment passes downwardly and, outwardly through the ilue 26, passing freely under the-bases of the stands on account of the spacing thereof above the platform 3 by their legs 28. In this way the to'p, the sides and the bottom of the pile of sheets I3 is uniformly and continuously heated. The stienlng Ts I2 extend at right angles from the side walls of the covers Il so as to prevent undesired expansion thereof which might permit warping of the covers and permit oxidizing gases to reach the plates beingiannealed.

Although I have shown and described herein a preferred embodiment of my invention, it -is to be denitely understood that I do not desire upper endl of the tile.

to limit the application of the invention thereto, and any change or changes may be made in the materials, and in the structure and arrangement` of the parts, within the spirit of the invention and the scope of the subjoined claims. f What is claimed is:-

-1. An annealing furnace of the character described comprising a top or cover portion, a base portion, said base portion containing a centralized flue and combustion chamber forming recesses provided with gas burner openings, said cover containing tile walls extending chordally therein and whose radially inward sides denne the annealing compartment and whose radially outward sides denne the upper' part of the combustion boxes registered with corresponding recesses in the base, said tile having openings establishing communication between the combustion boxes and the annealing compartment.

2. An annealing furnace of the character described comprising a cover including a metal shell provided with insulating material, tile walls ar-v ranged chordally within said cover so that their radialy inward sides define the annealing compartment and ,whose radially outward sides dene combustion boxes, and a base on which said cover rests, said base consisting of a metallicl shell having a filling of insulating material, said lling including a centralized ue communicating with the bottom of the annealing compartment and depressions fed by gas burner openings and registering with the combustion boxes, and said tile walls having openings establishing communication between the combustion boxes and the annealing compartment.

3. An annealing furnace of the character described comprising a cover including a metal shell provided with insulating material, tile walls arranged chordally within said cover so that their radially inward sides define the annealing compartment and whose radially outward sides dene combustion boxes, and a base on which said cover rests, said base consisting of a metallic shell having a filling of insulating material, said filling including a centralized flue communicating with the bottom of the annealing compartment and depressions fed by gas burner openings and registering with the combustion boxes, and said tile walls having openings establishing-communication be- ;tween the oombustionboxes and the annealing compartment, the openings in the tileA feeding the annealing compartment being at the lower end of the tile, and the openings in the tile in receiving arrangement to the combustion boxes being at the CLARENCE n. Hoax. 

